1. Field of the Invention
The present invention relates to a keypad panel, and in particular to a keypad panel assembly having a laterally-illuminated keypad surface.
2. Description of Prior Art
Keypad assembly is one of the primary input means for an electronic device. The surface of each keypad of the keypad assembly is provided with corresponding numerals, characters, phonetic symbols, roots for an input method and various functional icons, so that a user can input data or perform various functions of the electronic device. Therefore, for an electronic device, the keypad assembly is a very important input means.
When the electronic device is operated in an environment having sufficient illumination, the user can see the location of each keypad very clearly, so that the user will not press the wrong keypad in operation. However, in a dark or insufficiently-illuminated environment, it is difficult for the user to operate the keypads on the electronic device. Therefore, a backlight model is arranged in an inner layer of the keypad assembly. The light generated by the backlight model allows the user to see the location of each keypad and the icon displayed on the keypad surface very clearly even in a dark environment.
With reference to FIG. 1, the backlight model used in a traditional keypad assembly at least includes a light-guiding plate 10 and a light-emitting diode (electroluminescent plate) 20. When the electronic device is activated, after the light-emitting diode 20 is lighted up, the light 201 can be introduced from one side (or bottom) of the light-guiding plate 10, and then the light-guiding plate 10 projects the light on the bottom of each keypad 30. In this way, the light 201 passes through an icon 301 on the surface of the keypad 30 so as to display the icon 301 on the surface of the keypad 30, thereby avoiding the user from pressing the wrong keypad 30.
In order to allow the light to pass through the surface of the keypad 30 from the bottom of the keypad 30, the icon 301 on the surface of the keypad 30 is subjected to an etching or punching process to form a hollowed portion. Alternatively, via a printing or electroplating technique, a light-transmitting ink or color layer can be formed on the main body of the transparent keypad 30. As a result, the working hours and number of processes for manufacturing the keypads will be increased, which also increases the cost.